US 2003/0169606 A1 · Start-up circuit for switched mode power supply

Abstract

A switched mode power supply apparatus is equipped with a start-up device supplying electrical energy to a controller which controls the switching of a switching transistor. The start-up device is bypassed by a bypass-device. During start-up of the power supply, the bypass-device is open. After a successful start-up, the bypass-device will be closed, eliminating further dissipation in the start-up device, and therefore increasing the overall energy efficiency of the power supply. By connecting the start-up device to a stand-by power supply or to a primary voltage, use of an additional winding on the transformer to supply the controller is obviated. The power supply has an electronic overload protection, and will stop and periodically attempt a restart when an overload condition occurs.

Claims10

Dependent claims

A switched mode power supply for conversion of an input voltage into at least one output voltage, comprising:

an inductive device for transforming the input voltage into the at least one output voltage,
a switching device for periodically coupling the inductive device to the input voltage;
a controller for controlling the switching of the switching device, and
a start-up device for supplying electrical energy to the controller in a start-up phase, characterized in that the switched mode power supply further comprises a bypass-device coupled in parallel to the start-up device for bypassing the start-up device when the switched mode power supply is in regulation.

1 more element

Dependencies are inferred from the claim text.

Start-up circuit for switched mode power supply

Life of this patent

Start-up circuit for switched mode power supply

Life of this patent

Abstract

Claims10